(SeaPRwire) –
MSS colorectal cancer has been a dead zone for checkpoint inhibitors. PD-1 blockers work in MSIs, not MSS. Adding CTLA-4 creates dose-limiting toxicity. Adagene argues their masked antibody solves this. Peter Luo, Adagene’s R&D chief, claims the trial identifies the right dose for Phase 3. He highlights Sanofi’s equity investment as validation. The goal is to unlock value where legacy CTLA-4/PD-1 combos already hold FDA approval. This positions muzastotug as a backbone for early and late-line treatments.
Adagene completed enrollment in its randomized Phase 2 trial on November 9, 2026. Sixty patients participated. The trial tests muzastotug with Merck’s Keytruda in late-line MSS colorectal cancer without liver metastases. It follows a 2025 FDA meeting. The primary endpoint is overall response rate. Secondary metrics include duration of response, progression-free survival, and overall survival. Initial results are expected in the first half of 2027. This data will inform the Phase 3 dose regimen.
Two arms compete for the optimal protocol. Arm A uses 10 mg/kg every three weeks for four doses. It switches to 10 mg/kg every six weeks for maintenance. Arm B starts with 20 mg/kg every six weeks for two doses. Maintenance follows at 15 mg/kg every six weeks. Both use induction to activate the drug in tumors. Then maintenance sustains exposure. The FDA agreed with Adagene’s design. They accepted a standard-of-care control arm. No muzastotug monotherapy arm is required. The Phase 3 primary endpoint will be overall survival.
Adagene owns worldwide commercial rights to muzastotug. This asset targets a unique CTLA-4 epitope in regulatory T cells. The SAFEbody technology masks the binding domain. It activates only in the tumor microenvironment. This minimizes on-target off-tumor toxicity. The company leverages its Dynamic Precision Library platform. It combines computational biology and AI. The design addresses global unmet needs in solid tumors. The strategy avoids the toxicity traps of traditional CTLA-4 therapies.
The market implication is stark. MSS colorectal cancer lacks effective immunotherapy options. Legacy combinations struggle with toxicity and efficacy in this setting. Adagene’s approach targets the safety bottleneck directly. If the 1H 2027 data validates the dose, the path to Phase 3 is clear. The FDA endorsement of the trial design reduces regulatory risk. Investors should watch for the specific dose regimen selected. This choice dictates the future commercial viability and combination potential of the drug.